FROM ASTROPHYSICS
TO ASTROCHEMISTRY
TOWARDS ASTROBIOLOGY
IV Workshop della
Societa' Italiana di Astrobiologia
Dipartimento di Chimica,
Università degli Studi di Perugia
September 19-21, 2012
BOOK OF ABSTRACTS
Edited by Nadia Balucani
Virt&l-Comm is a new international online electronic scientific magazine offering a forum for presenting the work carried out by Virtual Innovation, Research, Teaching & Learning Communities. This magazine is the result of a joint endeavour of the COMPCHEM Virtual Organization (VO), of the European Chemistry Thematic Network (ECTN) Association and of the University of Perugia spinoff Master-Up.
Virt&l-Comm is a scholarly open access online Magazine requiring no payment neither from the authors nor from the readers.
Virt&l-Comm publishes at present two issues per year to promote Molecular and Materials Science, Teaching and Learning, Computer Science research. The magazine is also specialized in education and innovation and focuses on Service Oriented approaches. Therefore, in addition to articles, news, projects, reports of (successful or failed) attempts to build services relevant to the field of interest, lists of best practices, products used, the advantages and disadvantages of the solutions adopted will be considered for publication. In particular, all the information useful to build the puzzle of innovative complex applications in education (EDU), information and communication tecnology (ICT) and research and development (R&D) in Molecular and Materials science are welcome.
Editor-in-chief
ANTONIO LAGANÀ, Perugia (Italy)
NOELIA FAGINAS LAGO (deputy), Perugia (Italy)
Editorial board
RERINER SALZER, Dresden (Germany) ANTHONY SMITH, Lyon (France)
EVANGELIA VARELLA, Thessaloniki (Greece) LUCIANO MILANESI, Milano (Italy) STAVROS FARANTOS, Heraklion (Greece) IVAN CERNUSAK, Bratislava (Slovakia) LUCIANO GAIDO, Torino (Italy)
FROM ASTROPHYSICS
TO ASTROCHEMISTRY
TOWARDS ASTROBIOLOGY
IV Workshop della
Societa' Italiana di Astrobiologia
Perugia, Dipartimento di Chimica
September 19-21, 2012
SCIENTIFIC ORGANIZING COMMITTEE:
Nadia Balucani (Università di Perugia), John R. Brucato (Osservatorio di Arcetri), Vincenzo Aquilanti (Accademia dei Lincei), Piergiorgio Casavecchia (Università di Perugia), Ernesto Di Mauro (Università di Roma "La
Sapienza"), Enzo Gallori (Università di Firenze), Yeghis Keheyan (Università di Roma "La Sapienza"), Marco Moracci (CNR Napoli), Alessandra Rotundi (Universita' Parthenope, Napoli), Raffaele Saladino (Università della Tuscia), Gianni Strazzulla (Osservatorio di Catania)
LOCAL ORGANIZING COMMITTEE:
Nadia Balucani (Università di Perugia), Dimitrios Skouteris (Università di Perugia), Stefano Falcinelli (Università di Perugia), Andrea Lombardi
(Università di Perugia), Federico Palazzetti (Università di Perugia), Gabriele Pastori (Università di Perugia), Noelia Faginas Lago (MASTER-UP, Perugia), Domenico Stranges (Università di Roma "La Sapienza"), Yeghis Keheyan (Università di Roma "La Sapienza")
The cover picture has been shot by Nadia Balucani (with the help of Arianna and Dimitris Skouteris) at Sarakiniko (Milos, Cyclades Islands). It could represent one of the “warm little ponds” - far from the ocean currents - where the very first forms of life have originated, as suggested by Darwin.
IV Workshop Italian Astrobiology Society
“From Astrophysics to Astrochemistry towards Astrobiology” PROGRAMME
Wednesday, September 19 8.30 – 9.30
Registration 9.30
Welcome and opening remarks
(Prof. Fausto Elisei, Preside della Facoltà di Scienze MM FF NN; Prof. Antonio Laganà, Direttore del Dipartimento di Chimica; Dr. John R. Brucato, Presidente della Società Italiana di Astrobiologia)
10.00-10.45
Cecilia Ceccarelli (Institute de Planétologie et d'Astrophysique de Grenoble) Solicited Our Chemical Origins
10.45-11.30
Raul Baragiola (Univ. of Virginia)
UV -induced Molecular Synthesis below the Surface of Icy Satellites: Implications for Extraterrestrial Ice
11.30-12.00 Coffee Break
12.00-12.20
Angela Occhiogrosso (University College London)
Modelling of Methyl Formate Formation Towards Various Astronomical Environments 12.20-12.40
Savino Longo (Univ. Bari)
Simple models of meteor entry in planetary atmospheres 12.40-13.00
Tommaso Grassi (Univ. Roma “La Sapienza”)
Studying the Chemical Evolution of ISM Regions Via Numerical Methods
13.00-15.00 Lunch Break
15.00-15.45
Wolf D. Geppert (Stockholm Univ.) Solicited Formation of Biomolecule Precursors in Space 15.45-16.05
Cristina Puzzarini (Univ. Bologna)
16.05-16.25
Sonia Melandri (Univ. Bologna)
Flexibility in Complex Organic Molecules: a Challenge for Spectroscopy and Computational Methods
16.25-17.00 Coffee Break
17.00-17.20
John R. Brucato (INAF-Obs. Arcetri)
MarcoPolo-R: Asteroid Sample Return Mission 17.20-17.50
Renè Demets (ESTEC-Noordwijk) ESA Astrobiology – an Overview 17.50-18.10
Gian Paolo Tozzi (INAF-Obs. Arcetri)
Organic Ice in Comet 103P/Hartley 2 at the Time of the EPOXI Mission Fly-By 18.10-18.30
Franco Cataldo (INAF-Obs. Catania)
Solid State Radiolysis of Non-Proteinaceous Amino Acids: Astrobiological Implications 18.30-18.50
Nadia Balucani (Univ. Perugia)
The Reactions of Atomic Oxygen with Unsaturated Hydrocarbons in Extraterrestrial Environments
Thursday, September 20 9.00-9.45
Piero Ugliengo (Univ. Torino) Solicited
Interstellar Prebiotic Formation of Glycine, Delivery to Earth and Polymerization on Feldspars
9.45-10.05
Franco A. Gianturco (Univ. Roma “La Sapienza”)
Metastable Anions of C-rich Molecules: Dynamics and Role in Planetary Atmospheres and the ISM of Polyynes and PAHs
10.05-10.25
Silvano Onofri (Univ. Tuscia)
Safe Travelling Of Microbes Through Outer Space Within Rocks 10.25-10.45
Giovanni Strazzulla (INAF-Obs. Catania)
10.45-11.05
Oscar Trippella (Univ. Perugia)
Stellar Origin of Early Solar System Short-Lived Radioactivities and Their Role in Melting and Differentiating Solid Bodies
11.05-11.30 Coffee Break
11.30-12.15
Manuela Coci (Univ. Catania) Solicited
Lithotrophic Bacteria and Archaea in Aquatic Environments 12.15-12.35
Marco Casarosa (Univ. Firenze)
Evidence of DNA Primary Damage in Space Environment 12.35-12.55
Teresa Fornaro (INAF-Obs. Arcetri)
Adsorption of Nucleic Acid Bases on Magnesium Oxide (MgO): Hints of Life Detection on Mars
13.00-15.00 Lunch Break
15.00-15.45
Giacomo Certini (Univ. Firenze) Solicited Do Extraterrestrial Soils Exist?
15.45-16.05
Giovanni Vladilo (INAF – Trieste)
Studies of Planetary Habitability Performed with Energy Balance Climate Models 16.05-16.25
Eugenio Simoncini (INTA-CSIC, Madrid)
Thermodynamics Disequilibrium as a Parameter to Redefine Habitability 16.25-16.45
Guido Barone (Univ. Napoli “Federico II”)
The Possible Role of Clathrate Hydrates as Storage and Sink for Prebiotic Molecules in Extreme Conditions
16.45-17.15 Coffee Break
17.30-19.00
ROUND TABLE “Da Armstrong a Curiosity, da Marte alle galassie. Biomedicina spaziale e ricerca di vita aliena" presso la sala del 100dieci (Via Pascoli)
Cecilia Ceccarelli (Institut de Planétologie et d'Astrophysique de Grenoble); Mariano Bizzarri (Presidente del Consiglio Scientifico dell’Agenzia Spaziale Italiana, Università di Roma “La Sapienza”); Rene Demets (ESA-ESTEC); Valfredo Zolesi (Kayser Italia)
Moderatore: Fabio Pagan (Biologo, giornalista e divulgatore scientifico) SOCIAL DINNER
Friday, September 21 9.00-9.20
Giovanni Pratesi (Univ. Firenze)
Surface-Enhanced Raman Scattering Investigation of Nucleobases Adsorbed on a Martian Meteorite and Samples of Martian Analogue Material
9.20-9.40
Stefano Stranges (Univ. Roma “La Sapienza”)
Interaction of Chiral Molecules with Synchrotron Radiation: Enantioselective Study of Oxirane Derivatives
9.40-10.00
Alessandro Donati (Kayser Italia)
FEBO: an ASI Facility for Astro- and Exo- Biology Observations 10.00-10.20
Daniela Billi (Univ. Roma “Tor Vergata”)
Desert Cyanobacteria Go to ISS: Ground-based Simulations in Preparation of the EXPOSE-R2 Mission
10.20-10.40
Daniela Ascenzi (Univ. Trento)
Growth of Organic Molecules in Planetary Atmospheres Via Ion-Molecule Reactions 10.40-11.00
Domenico Stranges (Univ. Roma “La Sapienza”) Ultraviolet Photodissociation of Hydrocarbon Radicals
11.00-11.30 Coffee Break
11.30-11.50
Dimitrios Skouteris (Univ. Perugia)
N+O Associative Ionization with Formation of NO+: a Viable Route in the Interstellar Medium?
11.50-12.10
Marzio Rosi (Univ. Perugia)
Dimerization of Methanimine and Implications for the Atmosphere of Titan 12.10-12.30
Stefano Falcinelli (Univ. Perugia)
Dissociation of the CO2 Dications in the Upper Atmospheres of Planets - a New Route
of CO+ and O+ Formation
12.30-12.50
Federico Palazzetti (Univ. Perugia)
Chiral Effects in Oriented Molecules Collisions: Investigating the Origin of the Building Blocks of Life
LIST OF CONTRIBUTIONS
Solicited Talks
Raul Baragiola (Univ. of Virginia)
UV -induced Molecular Synthesis below the Surface of Icy Satellites: Implications for
Extraterrestrial Ice p. 3
Cecilia Ceccarelli (Institute de Planétologie et d'Astrophysique de Grenoble)
Our Chemical Origins p. 9
Giacomo Certini (Univ. Firenze)
Do Extraterrestrial Soils Exist? p. 10
Manuela Coci (Univ. Catania)
Lithotrophic Bacteria and Archaea in Aquatic Environments p. 11
Wolf D. Geppert (Stockholm Univ.)
Formation of Biomolecule Precursors in Space p. 18
Piero Ugliengo (Univ. Torino)
Interstellar Prebiotic Formation of Glycine, Delivery to Earth and Polymerization on
Feldspars p. 42
Oral Contributions
Daniela Ascenzi (Univ. Trento)
Growth of Organic Molecules in Planetary Atmospheres Via Ion-Molecule
Reactions p. 1
Nadia Balucani (Univ. Perugia)
The Reactions of Atomic Oxygen with Unsaturated Hydrocarbons in Extraterrestrial
Environments p. 2
Guido Barone (Univ. Napoli “Federico II”)
The Possible Role of Clathrate Hydrates as Storage and Sink for Prebiotic Molecules in
Extreme Conditions p. 4
Daniela Billi (Univ. Roma “Tor Vergata”)
Desert Cyanobacteria Go to ISS: Ground-based Simulations in Preparation of the
EXPOSE-R2 Mission p. 5
John R. Brucato (INAF-Obs. Arcetri)
MarcoPolo-R: Asteroid Sample Return Mission p. 6
Marco Casarosa (Univ. Firenze)
Evidence of DNA Primary Damage in Space Environment p. 7
Franco Cataldo (INAF-Obs. Catania)
Solid State Radiolysis of Non-Proteinaceous Amino Acids: Astrobiological
Renè Demets (ESTEC-Noordwijk)
ESA Astrobiology – an Overview p. 13
Alessandro Donati (Kayser Italia)
FEBO: an ASI Facility for Astro- and Exo- Biology Observations p. 14
Stefano Falcinelli (Univ. Perugia)
Dissociation of the CO2 Dications in the Upper Atmospheres of Planets - a New Route
of CO+ and O+ Formation p. 15
Teresa Fornaro (INAF-Obs. Arcetri)
Adsorption of Nucleic Acid Bases on Magnesium Oxide (MgO): Hints of Life Detection
on Mars p. 17
Franco A. Gianturco (Univ. Roma “La Sapienza”)
Metastable Anions of C-rich Molecules: Dynamics and Role in Planetary Atmospheres
and the ISM of Polyynes and PAHs p. 19
Tommaso Grassi (Univ. Roma “La Sapienza”)
Studying the Chemical Evolution of ISM Regions Via Numerical Methods p. 21 Savino Longo (Univ. Bari)
Simple models of Meteor Entry in Planetary Atmospheres p. 23
Sonia Melandri (Univ. Bologna)
Flexibility in Complex Organic Molecules: a Challenge for Spectroscopy and
Computational Methods p. 25
Angela Occhiogrosso (University College London)
Modelling of Methyl Formate Formation Towards Various Astronomical
Environments p. 28
Federico Palazzetti (Univ. Perugia)
Chiral Effects in Oriented Molecules Collisions: Investigating the Origin of the
Building Blocks of Life p. 30
Giovanni Pratesi (Univ. Firenze)
Surface-Enhanced Raman Scattering Investigation of Nucleobases Adsorbed on a
Martian Meteorite and Samples of Martian Analogue Material p. 31
Cristina Puzzarini (Univ. Bologna)
Astrophysical Investigations: the Role Of Rotational Spectroscopy p. 32
Marzio Rosi (Univ. Perugia)
Dimerization of Methanimine and Implications for the Atmosphere of Titan p. 33 Emanuele Simoncini (INTA-CSIC, Madrid)
Thermodynamics Disequilibrium as a Parameter to Redefine Habitability p. 34 Dimitrios Skouteris (Univ. Perugia)
N+O Associative Ionization with Formation of NO+: a Viable Route in the
Domenico Stranges (Univ. Roma “La Sapienza”)
Ultraviolet Photodissociation of Hydrocarbon Radicals p. 36
Stefano Stranges (Univ. Roma “La Sapienza”)
Interaction of Chiral Molecules with Synchrotron Radiation:
Enantioselective Study of Oxirane Derivatives p. 37
Giovanni Strazzula (INAF-Obs. Catania)
Energetic Processing of Ices and the Search for Life on Enceladus p. 38
Gian Paolo Tozzi (INAF-Obs. Arcetri)
Organic Ice in Comet 103P/Hartley 2 at the Time of the EPOXI Mission
Fly-By p. 39
Oscar Trippella (Univ. Perugia)
Stellar Origin of Early Solar System Short-Lived Radioactivities and
Their Role in Melting and Differentiating Solid Bodies p. 40
Giovanni Vladilo (INAF – Trieste)
Studies of Planetary Habitability Performed with Energy Balance Climate
Models p. 41
Poster Contributions
Michela Delfino (Univ. Tuscia)
Role of Iron Meteorites in the Prebiotic Chemistry of Formamide p. 12
Maria Carmina Ferrara (CNR – Napoli)
Glycosylation in the Crenarchaeon Sulfolobus Solfataricus p. 16
Yeghis Keheyan (ISMN-CNR)
Pyrolysis of Chiral Alcohols in the Presence of Catalysts of Interstellar
Interest p. 22
Assimo Maris (Univ. Bologna)
Is it possible to detect homodimers of organic acids in the interstellar medium or
circumstellar shells? p. 24
Marco Moracci, Rosa Giglio (CNR – Napoli)
Interrupted Genes in Early Organisms p. 26
Marco Moracci (CNR – Napoli)
Metagenomic Analysis of an Extreme Biotope p. 27
Alessandra Paladini (IMIP – CNR- Monterotondo)
CONTRIBUTIONS
1
Growth of organic molecules in planetary atmospheres via
ion-molecule reactions
Daniela Ascenzi, Paolo Tosi
Dipartimento di Fisica, Università di Trento, Via Sommarive 14, I-38123 Povo TN, Italy
e-mail: ascenzi@science.unitn.it
Unraveling the growth mechanisms of hydrocarbons (mainly aromatic and polyaromatic) is a challenging topic for understanding the chemical evolution of planetary atmospheres and the interstellar medium, where large molecules, mostly of organic nature, have been observed. Great effort is currently devoted to the modelling of the atmosphere of Titan, Saturn’s largest moon, where numerous heavy hydrocarbons and N-bearing species have been observed during the Cassini-Huygens mission [1]. PAH, nitrile aromatic polymers, fullerenes and polyphenyls have been proposed as potential candidates for the large mass cations and anions detected at ionospheric altitudes. An important role in the growth of large organic molecules is played by ion-molecule association reactions in particular those involving two medium sized pre-formed building blocks. Such type of processes have the advantage – over alternative mechanisms requiring sequential additions of small species - of attaining substantial growth in molecular size within a single reactive encounter.
To shed light on such mechanisms, we are investigating association processes affording covalently bound species, in particular C-C coupling reactions involving phenyl [2], ethyl [3], naphthyl [4] and biphenyl [5] cations with neutral arenes. Ion-molecule reactivity is investigated using tandem mass spectrometric techniques, which allow mass selection and manipulation of both reactant and product ions. The ion under study is generated by dissociative ionization of an adequate precursor, either in an electron impact ion source or in an atmospheric pressure chemical ionization APCI source. The latter source allows the generation of molecular ions with a lower degree of internal excitation than the former. We can estimate branching ratios of ionic products and absolute values of reactive cross sections as a function of the collision energy. A complementary experimental and theoretical approach is necessary to obtain reliable information on reaction mechanisms on systems with a large number of degrees of freedom. We use DFT methods to calculate energy and structures of the most relevant points on the reactive potential hypersurface.
[1] V. Vuitton, O. Dutuit, M. A. Smith, N. Balucani, “Chemistry of Titan's atmosphere” in Titan: Surface,
Atmosphere and Magnetosphere, I. Mueller-Wodarg, C. Griffith, E. Lellouch & T. Cravens, Eds.,
Cambridge University Press, 2012, in press.
[2] D. Ascenzi, N. Cont, G. Guella, P. Franceschi, P. Tosi, J. Phys. Chem. A, 111, 12513 (2007).
[3] J. Zabka, M. Polasek, D. Ascenzi, P. Tosi, J. Roithová, D. Schröder, J. Phys. Chem. A, 113 11153 (2009).
[4] D. Ascenzi, J. Aysina, P. Tosi, A. Maranzana, G. Tonachini, J. Chem. Phys. 133 184308 (2010). [5] J. Aysina, A. Maranzana, G. Tonachini, P. Tosi, D. Ascenzi, submitted to PCCP (2012).
2
The reactions of atomic oxygen with
unsaturated hydrocarbons in extraterrestrial environments
Nadia Balucani, Francesca Leonori, Angela Occhiogrosso, Luca Angelucci, Stefano Falcinelli, Domenico Stranges, Piergiorgio Casavecchia
Dipartimento di Chimica, Università di Perugia, 06123 Perugia, Italy e-mail: nadia.balucani@ unipg.it
The observation in hydrocarbon-rich planetary atmospheres and interstellar clouds of highly unsaturated organic molecules (such as acetylene) poses the question of how these molecules can survive in the upper atmospheres where atomic and radical species are relatively abundant. From a chemical point of view, indeed, each unsaturated C-C bond is a potential site for addition reactions especially when radicals are involved. Part of this puzzle is actually explained by the fact that the reactions of small alkynes, alkenes and dienes with several atomic and radical species (such as atomic carbon or CH, C2H, C2 and CN radicals) do not destroy the C-atom skeleton of
unsaturated species, but rather elongate it. Notable examples are the reactions between C, C2, C2H, CH, CN with acetylene (HCCH) and diacetylene (HCCCCH) which, in
laboratory experiments, have been verified to generate the products C3, C3H, C3H2,
C4H, C5H, C6H, C6H2, HC3N and HC5N [1]. Some of these species have been identified
in hydrocarbon-rich atmospheres, including the atmosphere of Titan or several interstellar objects. Quite interestingly, analogous oxygen-containing highly unsaturated species have not been identified and oxygen is mostly locked in CO2, H2CO and CO.
In our laboratory we have started a systematic investigation of several reactions involving atomic oxygen and unsaturated hydrocarbons (C2H2, C2H4, CH3CCH,
CH2=C=CH2) by means of the crossed molecular beam technique with mass
spectrometric detection and time-of-flight analysis [2-5]. Quite interestingly, we have observed that C-C bond fission channels are always relevant or dominant reaction pathways. The most illustrative case is the reaction between O and allene (CH2=C=CH2)
where ~ 90% of the reaction leads directly to the stable products CO+C2H4 [5], but also
significant fractions of the reactions O+C2H2and O+C2H4 lead to the products CO+CH2
and HCO+CH3, respectively [2,3]. In other words, the reactions of unsaturated
hydrocarbons with atomic oxygen are not only terminating the hydrocarbon growth in oxygen-rich environments, but are also able to convert relatively abundant and widely spread small unsaturated hydrocarbons directly into CO or its precursor HCO. Implications for the chemistry of the planetary atmospheres and interstellar medium will be noted.
[1] R.I. Kaiser, Chem. Rev., 102, 1309 (2002); R.I. Kaiser and N. Balucani, Acc. Chem. Res., 34, 699 (2001); R.I. Kaiser et al., Phys. Chem. Chem. Phys., 14 (2012); B. J. Sun, et al., J. Chem. Phys., 128, 244303 (2008); F. Zhang et al., J. Chem. Phys., 130, 234308 (2009); F. Zhang et al., J. Phys. Chem. A, 113, 1210 (2009).
[2] N. Balucani, F. Leonori and P. Casavecchia, Energy, 43 (2012) 47.
[3] B. Fu, Y.-C. Han, J.M. Bowman, L. Angelucci, N. Balucani, F. Leonori and P. Casavecchia, PNAS, 109 (2012) 9733.
[4] N. Balucani, F. Leonori, S. Falcinelli, D. Stranges, V. Nevrly and P. Casavecchia, in preparation. [5] F. Leonori, A. Occhiogrosso, N. Balucani, A. Bucci, R. Petrucci and P. Casavecchia, J. Phys. Chem. Lett., 3 75 (2012).
3
UV -induced molecular synthesis below the surface of icy
satellites: Implications for extraterrestrial ice
Raúl Baragiola, Jianming Shi, Ujjwal Raut, Jung-Hwan Kim
University of Virginia, Charlottesville, VA, USA.
Mark Loeffler
NASA Goddard Space Flight Center, Greenbelt, MD, USA.
The mass uptake of ambient oxygen in porous ice is enhanced by irradiation with 193 nm photons, due to conversion of O2 into H2O2 and O3. In the presence of
carbon, CO2 molecules are also formed. These findings show a new way to synthesize
molecules on icy surfaces in the outer solar system at depths much larger than are accessible by typical ionizing radiation, with possible astrobiological implications.
4
The Possible Role of Clathrate Hydrates as Storage and Sink
for Prebiotic Molecules in Extreme Conditions
Guido Barone,1 Elena Chianese2
1Dipartimento di Scienze Chimiche – Università di Napoli “Federico II” 2Dipartimento di Scienze Applicate – Università di Napoli “Parthenope”
The syntheses of gas chlatrates hydrates was well known from 1810 [1]. Up to he half last century these compounds remain confined as scientific curiosities. From the middle of ‘30 years, the engineers, managing petroleum pipelines in the cold regions (Siberia, Canada and Alaska), discovered the formation of some dirty crystals incrusting the pipes and often blocking the transmission of oil at temperatures near 0 °C or below [2-4].
Today the technological interest is devoted to ascertain the consistency and to study the possibility of exploiting the enormous reservoirs of natural gas clathrates present under the permafrost of circumarctica territories and under the soundings of continental escarpments and oceans In the following years the existence of large fields of methane and low hydrocarbon hydrates was ascertained in several places, especially under the sedimentary planes, the continental marine shelves and the off shore submarine rifts. Then high attention and economic and technological efforts were directed to the physical-chemical characterization of the hydrocarbon clathrate hydrates and to the exploration and exploitation of these new promising sources of energy [5-7].
In spite of the very large number of papers concerning the natural gas hosted in water clathrates, only few works treated the properties of clathrate hydrates of polar organic molecule [7-12]
Here we would like to summarize the known crystal structures of this kind of inclusion compounds and other physical chemical properties. On this basis we would discuss the possibility that solid cages of water molecules can include, store and protect prebiotic molecules or their precursors (in the extreme conditions of the solar system, as ice powders, inorganic dusts, solid surfaces and micropores), so acting as sinks and sources for more complex processes.
[1] H. Davy, Phil. Trans. Royal Soc. London, 101, 155-162 (1811). [2] E.G. Hammerschmidt, Ind. Eng. Chem., 26, 851-855, (1934). [3] B.A. Nikitin, Nature, 140, 643-643 (1937).
[4] D.L. Katz, R.L. Lee, Gas Hydrates and Their Prevention in Natural Gas Engineering, Production and
Storage, Chap. 5, (1990), Mc Grow & Hill.
[5]J. Carroll, Natural gas hydrates, a guide for Engineers, Gulf Professional Pub., Elsevier (2003). [6]E.D. Sloan, C.A. Koh. Clathrate Hydrates of Natural Gases (3rd ed), Taylor & Francis, CRC Press (2008).
[7] G. Barone, E.Chianese, Chem. Sus. Chem. 2, 992-1008 (2009).
[8] M. Luzi, J.M. Schicks, R. Naumann, J. Erzinger, K. Udachin, I. Moudrakowski, J.A. Ripmeester, R. Ludwig. Proceedings of the 6th International Conference on Gas Hydrates (ICGH 2008), Vancouver,
CANADA, (2008).
[10] P.T. Beurskens, G.A. Jeffrey. J. Chem. Phys., 40, 2800-2810; 41, 924-929, (1964). [11] R.K. Mc Mullan, G.A. Jeffrey, T.H. Jordan. J. Chem. Phys., 47, 1229-1234 (1967).
5
Desert cyanobacteria go to ISS: ground-based simulations in
preparation of the EXPOSE-R2 mission
Daniela Billi1, Mickael Baqué1, Jean-Pierre Paul de Vera2, Petra Rettberg3
1,University of Rome “Tor Vergata”, Department of Biology, Rome, Italy 2DLR Institute of Aerospace Medicine, Radiation Biology Department, Köln, Germany
2
DLR Institute of Planetary Research, Berlin, Germany
The Low Earth Orbit experiments BOSS (Biofilm Organisms Surfing Space) and BIOMEX (BIOlogy and Mars Experiment) are two interdisciplinary and international space research projects selected by ESA. The experiments will be accommodated on the space exposure facility EXPOSE-R2 on the International Space Station (ISS) and are foreseen to be launched in 2013. These two projects by focusing on extreme tolerant organisms and their cellular components, represent a follow up of previous astrobiology missions on platforms like EXPOSE and BIOPAN and of ground-based experiments, but also involve the exposure of new organisms and the use of novel approaches in astrobiology [1, 2].
BOSS aims to investigate the resistance of microbial biofilms compared to planctonic cultures. Biofilms are among the oldest clear signs of life on Earth and these might also be the first forms of life to be detected on other planets and moons of our solar system. BIOMEX investigates extreme tolerant organisms and their constituents (pigments and cell wall components) embedded within lunar and Mars regolith analogues. Such an approach will provide further understanding of the space resistance of life as we know it in the context of (litho-) panspermia and will contribute to realize a biosignature database for the search of life beyond Earth.
BOSS and BIOMEX experiments will include strains of the desert cyanobacterium Chroococcidiopsis; this cyanobacterium is a photosynthetic desiccation-, radiation-tolerant prokaryotes, that thrives in different deserts on Earth including the most extreme ones, like the Atacama Desert, Chile and Dry Valleys, Antarctica [3-5]. It has been selected for the next EXPOSE-R2 mission also because of its resistance to some space constraints tested on the previous space mission EXPOSE-E and ground simulations [6, 7]. Results on its survival and subcellular integrities after exposure to the newly performed ground simulations in preparation for the EXPOSE-R2 mission will be presented.
ILSRA-AO2009 projects BOSS-Cyano and BIOMEX-Cyano have been selected for funding by the Italian Space Agency.
[1] E. Rabbow, P. Rettberg, S. Barczyk, M. Bohmeier, A. Parpart, C. Panitz, et al., EXPOSE-E: An ESA Astrobiology Mission 1.5 Years in Space. Astrobiology 12, 374 (2012).
[2] J-P. de Vera, U. Boettger, R. de la Torre, F.J. Sánchez, D Grunow, N. Schmitz, C. Lange, H-W. Hüber, D. Billi et al., Planet. Space Sci., in press (2012).
[3] D. Billi, Subcellular integrities in Chroococcidiopsis sp. CCMEE 029 survivors after prolonged desiccation revealed by molecular probes and genome stability assays. Extremophiles, 13,49 (2009). [4] D. Billi, In: Adaptation of microbial life. Organisms in extreme environments: Novel research results
and application (eds Stan-Lotter H, Fendrihan F) Springer Wien-New York, pp 119 (2012).
[5] N. Stivaletta, R. Barbieri and D. Billi, Orig Life Evol Biosph., 42,143 (2012). [6] C.S. Cockell, P. Rettberg, E. Rabbow and K. Olsson-Francis, ISME J 5, 1671 (2011).
6
MarcoPolo-R: Asteroid Sample Return Mission
J.R. Brucato1, M.A. Barucci2, P. Michel3, A. Cheng4, H. Böhnhardt 5, E. Dotto6, P. Ehrenfreund7, I.A. Franchi8, S.F. Green9, L.-M. Lara10, B. Marty11, D. Koschny12,
D. Agnolon12, J. Romstedt12
1INAF-Obs. of Arcetri, I, 2LESIA-Observatoire de Paris, F, 3Univ. Nice, CNRS, OCA, F, 4JHU-APL,
Maryland, USA, 5MPS, Katlenburg-Lindau,, D, 6INAF-Obs. of Roma, I, 7Univ. of Leiden, NL, 8Open Univ., Milton Keynes, UK, 9Open Univ., Milton Keynes, UK, 10IAA-CSIC, Granada, E, 11CRPG, Nancy, F,12ESTEC, ESA, NL
MarcoPolo-R is a sample return mission to a primitive Near-Earth Asteroid (NEA) selected for the assessment study in the framework of ESA Cosmic Vision 2015-25 program. MarcoPolo-R is an European-led mission with a proposed NASA contribution. MarcoPolo-R will rendezvous with a primitive carbon-rich NEA, scientifically characterize it at multiple scales, and return a unique sample to Earth unaltered by the atmospheric entry process or terrestrial weathering.
The baseline target is a binary asteroid (175706) 1996 FG3, which offers a very efficient operational and technical mission profile. A binary target also provides enhanced science return. The choice of this target will allow new investigations to be performed more easily than at a single object, and also enables investigations of the fascinating geology and geophysics of asteroids that are impossible at a single object. Several launch windows have been identified in the time-span 2020-2024. The baseline mission scenario of MarcoPolo-R to 1996 FG3 foresees a single primary spacecraft, carrying the Earth re-entry capsule and sample acquisition and transfer system, launched by a Soyuz-Fregat rocket from Kourou.
The scientific payload includes state-of-the-art instruments, e.g. a camera system for high resolution imaging from orbit and on the surface, spectrometers covering visible, near-infrared and mid-infrared wavelengths, a neutral-particle analyser, a radio science experiment and optional laser altimeter. If resources are available, an optional Lander will be added to perform in-situ characterization close to the sampling site, and internal structure investigations.
MarcoPolo-R will allow us to study the most primitive materials available to investigate early solar system formation processes. The main goal of the MarcoPolo-R mission is to return unaltered NEA material for detailed analysis in ground-based laboratories. Only in the laboratory can instruments with the necessary precision and sensitivity be applied to individual components of the complex mixture of materials that forms an asteroid regolith, in orer to determine their precise chemical, mineralogical and isotopic composition. Such measurements are vital for revealing the evidence of stellar, interstellar medium, pre-solar nebula and parent body processes that are retained in primitive asteroidal material.
In addition to addressing the exciting science goals, the MarcoPolo-R mission also involves technologies for which technical development programmes are well under way. It is the ideal platform to (i) demonstrate innovative capabilities such as: accurate planetary navigation and landing, sample return operational chain; (ii) prepare the next generation of curation facilities for extra-terrestrial sample storage and analysis; (iii) develop high speed re-entry capsule; (iv) pave the way as a pathfinder mission for future sample returns from bodies with high surface gravity.
7
Evidence of DNA primary damage in space environment
Casarosa M.1-2, De Sio A.1, Pace E.1, Tozzetti L.1, and Gallori E.1
1XUVLab, Dipartimento di Fisica e Astronomia, Università degli Studi di Firenze, Italy 2
Dipartimento di Fisiopatologia Clinica, Università degli Studi di Firenze, Italy
The study of the interaction between radiation and complex organic biomolecules (nucleic acids, proteins) is one of the most important topics in Astrobiology, Astronautics, and Space Medicine. It is known that cosmic rays (CR), and SCR (secondary CR) are important factors of instability [1] for both the research of exogenous origin of life and for the security of astronauts during the space missions.
Many studies have been done concerning the behaviour of organisms and cells in space environment. However, results so far obtained are not sufficient to have a complete picture of this matter, in particular as for as is concerned the direct interaction between particle radiation present in space and genetic material.
The aim of this work was to characterize the typology of damages occurred on "naked" DNA after its exposition to the International Space Station (ISS) environment, To this aim, DNA samples were sent on the ISS with the STS 134 mission. During the flight (16/05/2011-30/05/2011), the genetic material was exposed to the same CR and SCR of the space crew. Subsequently, samples returned to the Earth were analyzed by gel-electrophoresis [2], to assess the presence and the nature of damages.
Results we have obtained, indicated that CR and SCR induced both single and double strand breaks on DNA. Moreover, it can be hypothesize the induction of substitutions, modifications and abasic sites on DNA sequence. These could be ascertained, in future experiments, by using specific restriction enzymes which recognize these kinds of damages.
[1] E.R. Benton et al., N.I.M., B 184, 255 (2001) [2] J.C. Sutherland et al., Electrophoesis, 22, 843 (2001)
8
Solid state radiolysis of non-proteinaceous amino acids:
astrobiological implications
Franco Cataldo,1 Susana Iglesias-Groth2
1Istituto Nazionale di Astrofisica – Osservatorio Astrofisica di Catania, Via S. Sofia 78, 95123
Catania, Italy
2
Instituto de Astrofisica de Canarias, Via Lactea s/n, E-38200, La Laguna, Tenerife, Spain
The analysis of the amino acids present in Murchison meteorite and in other carbonaceous chondrites has revealed the presence of 66 different types of amino acids. Only 8 of these 66 amino acids are proteinaceous amino acids used by the present terrestrial biochemistry in protein synthesis, the other 58 amino acids are somewhat “rare” or unusual or even “unknown” for the current terrestrial biochemistry. For this reason in the present work a series of “uncommon” non-proeinaceous amino acids, namely, L-2-aminobutyric acid, R(-)-2-aminobutyric acid, 2-aminoisobutyric acid (or α-aminoisobutyric acid), L-norleucine, L-norvaline, leucine, homoalanine, L-β-homoglutamic acid, S(-)-α-methylvaline and DL-3-aminoisobutyric acid were radiolyzed in vacuum at 3.2 MGy a dose equivalent to that emitted in 1.05x109 years from the radionuclide decay in the bulk of asteroids or comets. The residual amount of each amino acid under study remained after radiolysis was determined by differential scanning calorimetry (DSC) in comparison to pristine samples. For optically active amino acids, the residual amount of each amino acid remained after radiolysis was also determined by optical rotatory dispersion spectroscopy (ORD) and by polarimetry. With these analytical techniques it was possible to measure also the degree of radioracemization undergone by each amino acid after radiolysis. It was found that the non-proteinaceous amino acids in general do not show a higher radiation and radioracemization resistance in comparison to the common 20 proteinaceous amino acids studied previously. The unique exception is represented by α-aminoisobutyric acid which shows an extraordinary resistance to radiolysis since 96.6% is recovered unchanged after 3.2 MGy. Curiously α-aminoisobutyric acid is the most abundant amino acid found in carbonaceous chondrites. In Murchison meteorite α-aminoisobutyric acid represents more than 20% of the total 66 amino acids found in this meteorite.
[1] S. Iglesias-Groth, F. Cataldo, O. Ursini, A. Manchado, MNRAS, 410, 1447-1453 (2011). [2] F. Cataldo, O. Ursini, G. Angelini,S. Iglesias-Groth,A. Manchado, Rend. Fis. Acc. Lincei, 22, 8
9
Our Chemical Origins
Cecilia Ceccarelli
Institute de Planétologie et d'Astrophysique de Grenoble, F-38041 Grenoble Cedex 9 Cecilia.Ceccarelli@obs.ujf-grenoble.fr
The Solar System was born about 4.5 billions years ago from a condensation inside a cold (~10K) molecular cloud. What happened to that initial condensation and how did it evolved up to form the Earth and its environment that permitted life to thrive?
To answer these questions, we need to assemble many pieces of a giant puzzle that covers different fields. The chemical composition of comets and some parts of meteorites provide us with some precious pieces when it is compared to that in sources which will eventually become other Suns and planetary systems. For example, it tell us that Earth inherited water from cold iced bodies, that comets conserved only in part the imprint of interstellar chemistry while some pieces of meteorites have imprinted it forever, that nitrogen in comets is an heritage from different interstellar molecules, that deuterium in meteorites spots is inherited from the material of the primordial condensation. And all this tells us the story of how and from what the Earth and the Solar System bodies formed.
In this presentation, I will give an overview of the link between the interstellar chemistry and the Solar System origin.
10
Do extraterrestrial soils exist?
Giacomo Certini
Dipartimento di Scienze delle Produzioni Vegetali, del Suolo e dell’Ambiente Agroforestale (DiPSA), Università degli Studi di Firenze
Piazzale delle Cascine 28, 50144 Firenze, Italy
Soil lacks a universally accepted definition, partly because of its multifunctionality. One of the consequences is the ongoing debate on the possible occurrence of soils outside Earth. Space scientists often use the term regolith to refer to any loose extraterrestrial surface, but it is a too vague term, indicating any type of heterogeneous material covering solid rock. On our planet, soil form thanks to the combined action of at least five factors: parent rock, time, climate, topography, and biota. However, the necessity of biota is debated. In fact, important parts of Earth, such as the hyperarid Atacama Desert of Chile and the Dry Valleys of Antarctica, host virtually life-free soils with advanced horizonation, which is often considered a crucial feature of soil. Actually, although most people invokes the ability to support plant growth as sine qua non of soil, a scientific definition considers soil to be any in situ weathered veneer of a planetary surface that retains information on its climatic and geochemical history. For the author, a current or past chemical weathering is the pivotal requisite for soil.
What soil genesis cannot prescind from is a rocky parent material, which in the Solar System occurs in the four inner planets, a few moons, and the asteroids. On Earth, weathering is chiefly promoted by liquid water, which is the solvent where most of reactions happen and a carrier of matter and energy. Oxygen or, in anaerobic environments, weaker electron acceptor such as nitrates, sulphates and ferric iron allow the altering action of proton donors. Several sources of energy are finally the motor of pedogenesis. In extraterrestrial landmasses, most water probably occurs as ice, but weathering might be caused by thin layers of liquid water at the rock-ice interface, as documented to happen in frozen soils on Earth. Furthermore, there are several polar solvents able to replace liquid water, such as strong acids, ammonia, methanol and hydrazine. Finally, a variety of energy sources can drive chemical reactions in space: thermal, osmotic and ionic gradients, meteorite bombardment, solar wind and cosmic rays, magnetism and radioactivity are the most important ones.
Clear evidences of chemical weathering were found in the investigated surfaces of Mars, our moon, and the little asteroid Itokawa, which hence deserve the rank of soils.
A definition of soil that may represent a simple reliable point of reference for any terrigenous Outer Space landmass is provided.
11
Lithotrophic Bacteria and Archaea in aquatic environments
Coci Manuela1,2,3
1Molecular Microbiology and Antibiotic Resistance Laboratory, University of Catania, Italy 2
Aquatic Microbial Ecology , CNR- Institute of Ecosystem Study-Verbania, Italy
3 Microb&co Association
Over 8,000 species and nearly 1,550 genera of prokaryotes were tabulated as of 2007 (Taxonomic Outline of Bacteria and Archaea (TOBA 7.7, 2007) representing only the “tip of the iceberg” of the enormous diversity based on 16S ribosomal DNA in natural populations (Hugenholtz et al., 1998). Even though few, cultivated chemolithotrophic Bacteria and Archaea exhibit extraordinary diversity of substrates, physiology, modes of carbon nutrition, morphology and habitat, making artificial the grouping of chemolithotrophs into some kind of homogeneous taxonomic unit. To make
it more complex is that microorganisms proved to be facultatively
chemolithoautotrophs, mixotrophic or chemolithotrophic heterotrophs. The concepts of autotrophy (the assimilation of carbon dioxide as the major or sole source of biosynthetic carbon) and chemolithotrophy (growth with inorganic energy sources) thus were accepted as separate processes obligatorily linked in some specialized types of organisms. Reactions unequivocally established as sources of chemolithotrophic energy are the oxidation of hydrogen, ammonia, nitrite, sulfur and its reduced compounds, ferrous iron, and possibly cuprous copper, antimony, and uranium (IV). In particular reduction-oxidation reactions of nitrogen compounds offer a great potential of energy-generation by microorganisms. Surprisingly the discovery of new processes and players in the nitrogen cycle are quite recent: as for example, the discovery of anaerobic ammonia oxidation (anammox) in the early 1990’s and the cultivation of chemoautrophic Archaea nitrifiers in 2005 meaning that among known bacteria there is a great potential for chemolithotrophy and proving that a lot need still to be discovered. In addition, aquatic, that is marine, estuarine and freshwater and terrestrial environments are differently investigated and known with respect to the nitrogen cycle. Finally, chemiolithotrophic metabolisms lead to discussion relevant to the origin of life as well as to extraterrestrial systems.
12
Role of Iron Meteorites in the Prebiotic Chemistry of
Formamide
Michela Delfino,1 Raffaele Saladino,1 Giorgia Botta,1 Ernesto di Mauro,2 Giovanna Costanzo,2 Samanta Pino,2John Robert Brucato3
1
Biology and Ecology Department, University of Tuscia, 01100 Viterbo, Italy
2 Genetic and Molecular Biology Department, University La Sapienza, Rome Italy 3Astrophysical Observatory of Arcetri, Florence Italy
A variety of non-terrestrial amino acids similar to those found in life on Earth have been detected in meteorites. In addition to amino acids, sugar-like molecules, activated phosphates, and nucleobases have also been determined to be indigenous to numerous meteorites. Because these molecules are essential for life as we know it, it is plausible that the origin(s) of life on Earth was(were) aided by extraterrestrially-synthesized molecules. Understanding the role of meteorite in the prebiotic synthesis of biomolecules help to answer the question of whether biology is unique to Earth. [1]. Recently, during our studies on the prebiotic chemistry of formamide [2] we reported the efficient synthesis of nucleic acid derivatives in the presence of dust from the Murchison meteorite [3]. As a continuation of these studies here we describe the results of thermal condensation of formamide in the presence of various iron meteorites, including Campo del Cielo e Sikkolite. Simple heating the system to 60 °C in the presence of a catalytic amount of minerals afforded nucleic acids derivatives, amino acids, carboxylic acids and their derivatives (such as esters and amides) in high yield. Among the amino acids, the presence of unnatural derivatives, normally observed in non-terrestrial bodies, emphasizes the role played by the formamide as chemical probes for prebiotic processes in non-terrestrial environment. A comparison between the catalytic role of iron meteorites and Murchison and Orgueil carbonaceous chondrites will be also discussed.
[1] A. S. Burton, J. C. Stern, J. E. Elsila, D. P. Glavin, J. P. Dworkin, N. Balucani, Chem. Soc. Rev., 41, 5459-5472 (2012). [2] R. Saladino, G. Botta, S. Pino, G. Costanzo, E. Di Mauro (2012). Chem. Soc. Rev., (2012) ISSN: 0306-0012, doi: 10.1039/c2cs35066a. [3] R. Saladino, C. Crestini, C. Cossetti, E. Di Mauro, D. Deamer, OLEB, 41, 437-451, (2011).
13
ESA Astrobiology – an overview
René Demets
ESTEC (HSO-USL), Keplerlaan 1, NL-2201AZ Noordwijk, the Netherlands Rene.Demets@esa.int
History:
Between 1992 and 2012 eight sets of astrobiological experiments from the European Space Agency (ESA) were flown in low-Earth orbit to expose biological and
biochemical test samples to the harsh space environment. The flight duration varied from 12 days to 22 months. The total number of experiments was 60. The samples were analysed on ground after the flight, there was no monitoring in space.
Flight equipment:
Four different exposure facilities were used: ERA, BIOPAN, EXPOSE and STONE. The first three were aimed to investigate the effects of vacuum, full-spectrum solar light, freeze/thaw cycles, cosmic radiation and microgravity. STONE was conceived to test the effects of atmospheric entry.
Some results:
- Survival of particular terrestrial organisms was demonstrated after up to 22 months of space exposure;
- Among the survivors were macroscopic eukaryotic organisms like lichens and plant seeds;
- The most lethal space factor was solar UV. Protected against UV even more organisms were able to survive;
- Survival is restricted to organisms able to enter into dormancy; - Space exposure had no effect on the chirality of organic molecules; - Sedimentary rocks remained intact during atmospheric entry.
The new results from the 18-month EXPOSE-E mission have just been published [1]. Prospects for the future:
EXPOSE is planned for a new flight in 2013-2015 on the ISS, loaded with four
experiments. A new development is OREOCUBE, also on the ISS, designed to monitor UV processing of organic molecules during flight. The European EXOMARS rover is slated for launch by the end of this decade. Equipped with a drill, EXOMARS can collect and analyse Martian soil samples from 2 meters depth.
14
FEBO: an ASI Facility for Astro-
and Exo- Biology Observations
A. Donati, G. Neri, V. Zolesi
Kayser Italia, Livorno
Space biology with the disciplines of astrobiology, exobiology and radiation biology requires experiments directly exposed to space environment for short, medium and long periods of time. These experiments can require direct exposure to space environment for studies on UV and solar radiation, on cosmic radiation and on particles at high altitudes. The FEBO program of the Italian Space Agency (ASI), that has recently concluded successfully its Phase B, can provide the suitable environment and resources necessary to accommodate most of the above mentioned disciplines outside the International Space Station (ISS). The status of the program, together with the wide application capabilities of the FEBO platform and the already identified candidate experiments are described. Finally, the new payload upload and download scenarios after the retirement of the Space Shuttle has been assessed, confirming the full possibility to bring to completion the program.
15
Dissociation of the CO
2dications in the upper atmospheres of
planets - a new route of CO
+and O
+formation
M. Alagia1, P. Candori2, S. Falcinelli2, F. Pirani3, R. Richter4, S. Stranges5,1, F. Vecchiocattivi2
1
IOM-CNR, Laboratorio TASC, I-34149 Basovizza, Trieste, Italy
2 Dipartimento di Ingegneria Civile ed Ambientale, Università di Perugia, 06125 Perugia, Italy 3 Dipartimento di Chimica, Università di Perugia, 06123 Perugia, Italy
4 Sincrotrone Trieste, Area Science Park, 34149 Basovizza, Trieste, Italy 5
Dipartimento di Chimica, Università di Roma “La Sapienza”, 00185 Rome, Italy
The first observation of the CO22+ dication formed by electron impact ionization
of carbon dioxide was reported in 1961 [1]. Since that experiment, the double ionization of CO2 has been studied in several laboratories [2–5]. These kinds of
processes are of great interest because of the involvement of CO2 in several
atmospheric phenomena of the Earth and of other planets and in plasma environments. In Mars’ atmosphere, where CO2 is the main component, the importance of the CO22+
dication and its dissociation has been recently demonstrated [6]. In this contribution we present a double photoionization of CO2 molecules studied in the 34-50 eV photon
energy range, by the use of synchrotron radiation and detecting electron-ion and electron-ion-ion coincidences. The experiment has been carried out at the synchrotron light laboratory ELETTRA (Trieste, Italy) by the use of the ARPES end station of the Gas Phase Beamline [7,8]. The CO2 molecular beam and the vuv light beam cross at
right angles, with the light polarization vector being parallel to the synchrotron ring plane and perpendicular to the time-of-flight direction of detected ions. Three processes have been observed: (i) the formation of the CO22+ molecular dication, (ii) the
production of a metastable (CO22+)* that dissociates, with an apparent lifetime of 3.1 μs,
giving rise to CO+ and O+ ions, and (iii) the dissociation leading to the same products, but occurring with a lifetime shorter than 0.05 μs. In the photon energy range investigated, the double dissociative photoionization reaction of CO2 leads to an
isotropic distribution of CO+ and O+ product ions with respect to the polarization vector of the light. When the photon energy increases, the distribution of products becomes anisotropic, with the two ions preferentially emitted along the direction of the light polarization vector. This implies that the molecule photoionizes when oriented parallel to that direction and also that the CO22+ dication just formed dissociates in a
time shorter than its typical rotational period. At low photon energy, the CO+ and O+ product ions separate predominantly with a total kinetic energy between 3 and 4 eV. This mechanism becomes gradually less important when the photon energy increases and, at 49 eV, a process where the two products separate with a kinetic energy between 5 and 6 eV is dominant.
[1] F. H. Dorman and J. D. Morrison, J. Chem. Phys., 1961, 35, 575. [2] D. Mathur, Phys. Rep., 1993, 225, 193. [3] Z. D. Pesic, D. Rolles, R. C. Bilodeau, I. Dimitriu and N. Berrah, Phys. Rev. A: At., Mol., Opt. Phys., 2008, 78, 051401 and references therein. [4] A. E. Slattery, T. A. Field, M. Ahmad, R. I. Hall, J. Lambourne, F. Penent, P. Lablanquie and J. H. D. Eland, J. Chem. Phys., 2005, 122, 084317. [5] K. Ueda and J. H. D. Eland, J. Phys. B: At., Mol. Opt. Phys., 2005, 38, S839. [6] C. Nicolas, C. Alcaraz, R. Thissen, J. Zabka and O. Dutuit, Planet. Space Sci., 2001, 50, 877; O. Witasse, O. Dutuit, J. Lilensten, R.Thissen, J. Zabka, C. Alcaraz, P. L. Blelly, S. W. Bougher, S. Engel, L. H. Andersen and K. Seiersen, Geophys. Res. Lett., 2002, 29, 1263. [7] M. Alagia, P. Candori, S. Falcinelli, M. Lavolleé, F. Pirani, R. Richter, S. Stranges, and F. Vecchiocattivi, J. Chem. Phys. A, 2009, 113, 14755; M. Alagia, P. Candori, S. Falcinelli, M. Lavolleé, F. Pirani, R. Richter, S. Stranges, and F. Vecchiocattivi, Phys. Chem. Chem. Phys., 2010, 12, 5389. [8] M. Alagia, C. Callegari, P. Candori, S. Falcinelli, F. Pirani, R. Richter, S. Stranges, and F. Vecchiocattivi, J. Chem. Phys., 2012, 136, 204302.
16
Glycosylation in the crenarchaeon Sulfolobus solfataricus
Maria Carmina Ferrara1, Beatrice Cobucci-Ponzano1, Andrea Carpentieri2, Angela Amoresano2 and Marco Moracci1
1
Institute of Protein Biochemistry, CNR, Via P. Castellino 111, 80131, Naples, Italy,
2
Department of Chemical Sciences, University of Naples “Federico II”, Naples, Italy. Glycosylation, once believed to be restricted to Eukarya, is one of the most prevalent posttranslational modifications in organisms of all domain of life, expanding the diversity of the proteome by the addition of different glycan moieties. The first example of prokaryotic Nglycosylated protein was reported in the haloarchaeon Halobacterium salinarum [1], and from this discovering, it is now clear that the prevalence and the structural variety of the N-glycosylated proteins are more prominent in Archaea than in Bacteria. In the N-glycosylation pathway, Archaea combines particular aspects of the bacterial and eukaryal pathways, such as monomeric oligosyltransferases and dolichol phosphate carrier respectively, along with traits unique to this life form [2]. The majority of the data available concerns euryarchaeal model species [3]. Preliminary studies on Crenarchaea, a phylum evolutionarily distant from Euryarchaea, indicate that glycosylation is indispensable for cell survival [4] and even more widespread than in Euryarchaea [5]. Nevertheless, little is know about the nature of the glycosylated proteins and the machinery involved in the crenarchaeal glycosylation.
Here, we report the identification and biochemical characterization of a novel β-glucosidase/β-Nacetylglucosaminidase in Sulfolobus solfataricus P2. The enzyme is encoded by the ORF SSO3039, and represents the first member of the family GH116 (http://www.cazy.org) able to hydrolyze Nacetyl-β-D-glucosaminides. In addition, by using a glycoproteomic approach, we analyzed the sugar composition and structure of the glycoproteins from S. solfataricus.
A better understanding of crenarchaeal glycosylation will provide new insights into this posttranslational modification across evolution as well as adaptation to extreme conditions.
[1] M.F. Mescher and J.L. Strominger Journal of Biological Chemistry, 251 2005, (1976) [2] D. Calo, L. Kaminski and J. Eichler, Glycobiology, 20, 1065 (2010)
[3] M. Abu-Qarn and J. Eichler, Molecular Microbiology, 61, 511, (2006)
[4] A.C. Lindås, E.A. Karlsson, M.T. Lindgren, T.J. Ettema and R. Bernander, Proc Natl Acad Sci USA,
105, 18942,
(2008)
17
Adsorption of Nucleic Acid Bases on Magnesium Oxide
(MgO): hints of life detection on Mars
Teresa Fornaro
INAF- Astrophysical Observatory of Arcetri, Florence, Italy. fornaro@arcetri.astro.it
John Robert Brucato
INAF- Astrophysical Observatory of Arcetri, Florence, Italy. jbrucato@arcetri.astro.it
Sergio Branciamore
INAF- Astrophysical Observatory of Arcetri, Florence, Italy. sergio.branciamore@gmail.com
Amaranta Pucci
INAF- Astrophysical Observatory of Arcetri, Florence, Italy. pucci@arcetri.astro.it
The adsorption of organic molecules on mineral matrices might have played a fundamental role in processes that led to the emergence of life. We investigated the adsorption properties of the nucleobases adenine, cytosine, uracil and hypoxanthine on magnesium oxide (MgO), determining the single solute batch equilibrium adsorption isotherms. Langmuir-type isotherms were fitted to data, assuming a rapid reversible equilibration of adsorption, demonstrated effectively through desorption experiments. The Langmuir equilibrium adsorption constant K and the amount of the solute per unit of adsorbent mass necessary to complete the monolayer b were calculated. The results indicate that magnesium oxide is a good adsorbent for nucleobases (adenine > uracil > hypoxantine > cytosine), suggesting a role of metal oxides in concentrating biomolecules in prebiotic conditions that might have favored the passage from geochemistry to biochemistry.
18
Formation of biomolecule precursors in space
Wolf D. Geppert1,2
1 Stockholm University Astrobiology Centre 2
Physics Department, Stockholm University, Sweden
The possibility of an extraterrestrial origin of biomolecule building blocks has been a subject of intense discussions for many years. The detection of amino acids in meteorites opens the possibility of a delivery of biomolecules synthesized in the interstellar medium or star-forming regions to the primeval Earth. Whereas it can be doubted if more complex species like amino acids and carbohydrates can survive the strong UV radiation in the early Solar System, this does not necessary hold for more primitive precursor molecules like alcohols and nitriles. [1]
If these compounds can be synthesised in the interstellar medium, the question of their formation sites and pathway arises. It has been a long-standing issue to what extent comparatively complex carbon-containing interstellar molecules like methanol, ethanol, dimethyl ether and formic acid are produced in the gas-phase or on grain surfaces. I will discuss possibilities to solve these questions through experimental, computational and observational studies.
Nitriles can serve as amino acid and nucleobase precursors can also be synthesized very efficiently in methane-nitrogen dominated atmospheres like the one present on Titan and, possibly, the early ages of Earth. Therefore I will also discuss the formation and degradation processes of nitriles in Titan's atmosphere and on their possible role in the generation of biomolecules.
[1] M. P Bernstein, S. F. M. Ashbourn, S. A.; Sandford, L. J., Allamandola, Astrophys. J., 601, 365 (2004)
19
Metastable anions of C-rich molecules: Dynamics and role in
planetary atmospheres and the ISM of polyynes and PAHs
Franco A. Gianturco
Department of Chemistry , the University of Rome La Sapienza, 00185 Rome, Italy
The recent discoveries of the C3N and C5N radicals [1] and of the confirmed
presence of the C3N- and C5N- anions in circumstellar envelopes [2,3] have triggered a
great deal of interest on the characterization of the specific properties of the linear carbon chains of the type C2n+1N. In particular, the C3N and the C5N radicals and their
anionic counterparts were discovered in the expanding circumstellar envelope of the carbon star IRC+10216 and in the dark cloud TMC1, using radiotelescopes: they are key cyanopolyacetylides and constitute important drivers of interstellar chemistry as are seen as potentially significant constituents of Titan’s atmosphere[4]. It is therefore of current interest to revisit the formation processes of the observed linear anions ( for example, C3N- and C5N-) by considering the dynamics, at the molecular level, of the
environmental electrons which can undergo scattering from closed shell species which could thus provide the precursors species in the planetary atmospheres: examples are given by the HC3N and HC5N neutral polar partners but other ,similar processes also
involve nonpolar species like HC2H, HC4H or NC2N and NC4N. We wish to study here
the structures and localizations of possible resonances (metastable compound states) which can originate from the quantum interaction between the above molecules and the “hot” electrons expected to be present in the planetary and protoplanetary atmospheres mentioned at the beginning, in order to link to each of such resonances a specific stabilization path which could lead to the formation of the observed anions of the C2n+1N- type, or of the HCn- and Cn- types as detected in the interstellar medium (ISM)
as smaller fragments of the CnH variety after dissociative electron attachment in
multidimensional molecular space. In the previous studies on the formation rates and mechanisms for CnH anions in interstellar and circumstellar media it was pointed out
that, since the binding energy of an electron to a neutral species (i.e. its electron affinity, EA) is typically smaller in energy than the average chemical bond (which is usually around 4 eV), then the dissociative attachment process is normally an endothermic one:
M--H + e- [MH-]* M- + H
Therefore, in order for the DEA process to take place at low temperatures and for low-energy electrons (that is in order to be an exothermic event) there must be a weakening of one or more of the relevant bonds during the formation of a metastable precursor state, [MH-]*, in reaction above. The present analysis of such "weakening" events in the broad variety of linear molecules we are considering is therefore based on: (i) the formation of a metastable anion in the continuum for lifetimes at least comparable with that of a vibrational mode; (ii) the existence of additional antibonding features along a specific bond (the "weakening effect") caused by the newly attached electron; (iii) the partial or total redistribution of the excess electron energy within the internal molecular bonds (intramolecular vibrational redistribution, IVR) and (iv) possible radiative stabilization of an anionic fragment corresponding to one of the species experimentally observed. In the analysis of the quantum dynamics which we shall be presenting at the talk we shall therefore focus on the features of the resonant, intermediate complexes, i.e. of the possible metastable anionic states formed by electron attachment in neutral, closed-shell linear molecules which are expected to act as "doorway" states to the ensuing formation of stable negative ions after fragmentation. We shall be able to
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provide evidence that only those metastable states which correspond to long-lived electron attachment states, and which occur for near-threshold electron projectiles, have a realistic chance of competing successfully with the autodetachment channels and therefore manage to stabilize anionic species. The latter shall be either of the unfragmented molecule or shall identify specific fragments of the latter , depending on the bond weakening effects caused by the metastable excess electrons.Examples of the various options in anionic stabilization paths will be given during the present talk.
[1] e.g. see: R.R. Lucchese, F.A. Gianturco, Int. Rev. Phys. Chem. 15, 429 (1996)
[2] S.L. Altman, P. Herzig, Point-group Theory Tables; Oxford University Press: Oxford, U.K. 1994 [3] R. Curik, F.A. Gianturco, R.R. Lucchese, N. Sanna, J. Phys. B 34, 59 (2001)
[4] T. Stoecklin, F.A. Gianturco, Eur. Phys. J. D 42, 85 (2007) [5] T. Stoecklin, F.A. Gianturco, Chem. Phys. 332, 145 (2007) [6] T. Stoecklin, F.A. Gianturco, Eur. Phys. J. D 40, 369 (2006) [7] F. Sebastianelli, F.A. Gianturco, Eur. Phys. J. D 59, 389 (2010)
[8] F. Sebastianelli, F. Carelli, F.A. Gianturco, Chem. Phys. In press
(2011)doi:10.1016/j.chemphys.2011.08.004
[9] E. Herbst, Y. Osamura, Astrophys. J. 679, 1670 (2008)
[10] N. Sakai, T. Sakai, S. Yamamoto, Astrophys. J. 673, L71 (2008)
[11] A.J. Remijan, J.M. Hollis, F.J. Lovas, M.A. Cordiner, T.J. Millar, A.J. Markwick-Kemper, P.R. Jewell,Astrophys. J. 664, L47 (2007)
[12] P. Botschwina, Mol. Phys. 103, 1441 (2005)
[13] M. Allan, O. May, J. Fedor, B.C. Ibanescu, Phys. Rev. A 83, 052701 (2011)
[14] V. Vuitton, P. Lavvas, R.V. Yelle, M. Galand, A. Wellbrock, G.R. Lewis, A.J. Coates, J-E. Wahlund,Planet. and Space Sci. 57, 1558 (2009).
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Studying the chemical evolution of ISM regions
via numerical methods
T. Grassi, F. Carelli, F.A. Gianturco
Department of Chemistry , the University of Rome La Sapienza, 00185 Rome, Italy
Chemistry is one of the most important ingredients in many astrophysical simulations. Unfortunately chemical processes consist of a large ensemble of reactions that are computationally expensive when embedded into more complex and realistic ISM simulations.
Moreover, there are large uncertainties related to the rate coefficients that in turn determine equally large uncertainties in the ISM model evolutions.
In this framework we present and discuss a novel network-reducing technique which allows marked reductions of the computational times and we shall illustrate the
influence of some ab initio calculations of reaction rates involving PAHs on the overall chemical evolutions in dark molecular clouds.
